Isuzu 2008MY N Series Workshop Manual page 349

1A-346 Engine Control System (4HK1)
Checks
Duplicating Failure Conditions
Scan Tool Snapshot
DRM Memory
• If none of the previous tests are successful, attempt to duplicate and/ or
capture the failure conditions.
• Freeze Frame/ Failure Records data, where applicable, contains the
conditions that were present when the DTC set.
- Review and record Freeze Frame/ Failure Records data.
- Operate the vehicle under the same conditions that were noted in
Freeze Frame/ Failure Records data, as closely as possible. The vehicle
must also be operating within the Conditions for Running the DTC.
Refer to Conditions for Running the DTC in the supporting text of the
DTC being diagnosed.
• An alternate method is to drive the vehicle with the DMM connected to a
suspected circuit. An abnormal reading on the DMM when the problem
occurs, may help you locate the problem.
The scan tool can be set up to take a Snapshot of the parameters available via
serial data. The Snapshot function records live data over a period of time. The
recorded data can be played back and analyzed. The scan tool can also graph
parameters singly or in combinations of parameters for comparison. The
Snapshot can be triggered manually at the time the symptom is noticed, or set
up in advance to trigger when a DTC sets.
An abnormal value captured in the recorded data may point to a system or
component that needs to be investigated further.
Refer to the scan tool Users Guide for more information.
Use data stored in the DRM memory or use manual trigger function. The DRM
has ability to store engine log data when an event of DTC. The manual trigger
function is to store the log data by an arbitrary operation of the driver when an
event of wrong vehicle performance that is instead of an event of DTC. If the
driver presses and releases the manual trigger switch once, that time becomes
a trigger and one log data before and behind the trigger is stored in the DRM
memory.
Refer to the DRM Users Guide for more information.
Action